Q226
A man is twice as fast as a women and a woman is twice as fast as a boy in doing a work. If all of them, a man , a woman and a boy can finish the work in 7 days, a boy will do it alone ?
A.
49 days
AnswerB.
7 days
C.
6 days
D.
42 days
Answer: Option A
Solution
Answer: Option A
Solution:
| Man | : | Woman | : | Boy | |
| Efficiency | 4 | : | 2 | : | 1 |
Total work = Time × (Efficiency of man + woman + boy)
⇒ 7 days × (4 + 2 + 1) = 49 units
∴ Boy can do this work in = = 49 days